Feeding device for a rotary tablet machine

ABSTRACT

A feeding device for a rotary tablet machine includes a frame with partitions defining communicating receiving and delivery compartments, the frame being mounted above a rotary table wherein molds are arranged. In accordance with the invention, the partitions of the frame have apertures made therethrough across the molds these apertures establishing communication of the interiors of the molds with the ambient atmosphere, as each mold is being filled with a powder, the delivery compartments having therein blade-type agitators for feeding the powder.

United States Patent [191 Talis et al.

[ Oct. 7, 1975 FEEDING DEVICE FOR A ROTARY TABLET MACHINE [76] Inventors: Nikolai Semenovich Talis, ulitsa Zhelyabova, 13, kv. 28; Vitaly lvanovich Matjushenko, ulitsa Sovetskaya, l0, kv. 21, both of Angarsk, U.S.S.R.

[22] Filed: Dec. 21, 1973 [21] Appl. No.: 427,410

[52] US. Cl. 425/209; 425/348; 425/345; 425/812 [51] Int. Cl. B30B 15/30 [58] Field of Search 425/352, 353, 354, 348, 425/812, 78, 209, 345

[56] References Cited UNITED STATES PATENTS 2,270,829 1/1942 Wellnite 425/209 2,949,082 8/1960 McCarley 425/353 3,326,145 6/1957 Austin 425/453 FOREIGN PATENTS OR APPLICATIONS 256,178 3/1970 U.S.S.R 425/354 Primary Examiner-Francis S. Husar Assistant Examiner-David S. Safran Attorney, Agent, or Firm-Waters, Schwartz & Nissen [57] ABSTRACT A feeding device for a rotary tablet machine includes a frame with partitions defining communicating receiving and delivery compartments, the frame being mounted above a rotary table wherein molds are arranged. In accordance with the invention, the partitions of the frame have apertures made therethrough across the molds these apertures establishing communication of the interiors of the molds with the ambient atmosphere, as each mold is being filled with a powder, the delivery compartments having therein bladetype agitators for feeding the powder.

2 Claims, 4 Drawing Figures US. Patent Oct. 7,1975 3,910,739

1 Y FEEDING DEVICE FOR A ROTARY TABLET MACHINE The presentinvention relates to the art of pressure treatment of materials, and, more particularly, it relates to rotary tablet compressing machines, the invention being aimed in particular at improving the construction of a feeding device of a rotary tablet compressing machine.

There are known feeding devices for rotary tablet compressing machines (see, for example, U.S. Pat. No. 2,043,086) including a frame or grid with partitions defining a receiving compartment and delivery compartments, communicating with one another. As the rotor of the machine is rotating, the powder is fed into the receiving compartment, which powder is made to flow by the rotation of the table into each one of the communicating compartments, wherefrom it flows into the internal cavities of the molds mounted in the table of the rotor.

A disadvantage of this known structure arises from the fact that the air leaving the inlets of the molds, as the powder is poured thereinto, has to pass through the powder body in the feeding device. Consequently, the powder handled by the tablet machine is to be subjected to a treatment rendering it air-permeable, this treatment involving substantial extra costs. However, even when the powder is thus treated, it nevertheless displays some resistance to the flow of the air leaving the inlets of the molds, whereby the effectiveness of filling of the molds is affected. Furthermore, as the air permeability of the powder at different portions of the powder body is apt to be different, there results nonuniformity of filling of the molds with the powder, which affects the quality of compressed articles.

It is, therefore, an object of the present invention to reduce the time of filling of the molds with the powder and to improve the quality of the compressed articles.

The present invention has for its object the construction of a feeding device for a rotary tablet compressing machine, which provides for a better quality filling of the molds. This object is attained by partitions of the frame, having apertures made therethrough, adapted to establish communication between the interior of each mold and the ambient atmosphere, as the molds are being filled with the powder.

According to a preferred embodiment of the present -'"FIG."'4 is'a sectional view taker'i along line IV-IV of FIG. 2.

Referring now in particular to the appended drawing, the inventive feeding device for a rotary powder compressing tablet machine is mounted on posts 1 (see FIG. 1) secured to the framework of the tablet machine. The 'feedi'ng device is positioned to adjoin the plane'of a rotary mold table 2 of the'machine for carrying molds 6, driven by a rotor 2a (shown in FIG. 4).

Thus, the feeding device for the rotary tablet machine is non-rotatably mounted above the rotary mold table 2 and includes a frame or grid 3 with partitions 3a (FIG. 2) which define a receiving compartment 4 and delivery compartments 5. The partitions of the frame 3 have passages (not shown in the appended drawing) made therein to ensure communication between all the compartments 4 and 5. The frame of the feeding device in a bronze casting and presents a shell of a closed contour and specified height.

Along a circular path of the molds 6, apertures 7 are made through the partitions 3a of the frame 3, thinwalled tubes 8 being pressure-fitted in these apertures 7 (see FIG. 3). The delivery compartments 5 have horizontal spindles or shafts 9 (FIG. 3 and FIG. 4) journalled in their walls, the shafts ending with bevel gears 10 mounted in a cantilever fashion thereon, the gears meshing with a toothed rim 11 of the rotor 2a of the tablet machine (see FIG. 4).

The shafts 9 have spaced agitator blades 12 mounted on that part of each shaft which is received within the respective compartment 5, the agitator blades extending perpendicularly to the axis of rotation of the respective shaft. The delivery compartments 5 are closed from above with a lid 13.

In operation of the tablet machine, as the rotor 2a thereof is rotating, the powder is supplied into the receiving compartment 4 of the frame and flows under the action of rotation of the mold table 2 into each one of the delivery compartments 5 communicating with one another, without filling the spaces closed off by the tubes 8. The molds 6 mounted in the mold table 2 are brought in succession by rotation of the rotor to the partitions 3a of the frame 3. The powder is acted upon by the rotation of the table and by the rotating bladetype agitators 12 in the molds 6, while the air is expelled from the internal space of the mold by the incoming powder through the apertures 7 defined by the invention, it is advisable that the delivery compartments of the feeding device have blade-type agitators the spindles being driven from the toothed rim of the rotor.

For the essence of the present invention to be better understood, there follows hereinbelow the detailed description of an embodiment of the invention, with reference being had to the accompanying sheet of drawings, wherein:

FIG. 1 is a partly sectional view of the inventive feeding device for a rotary tablet compressing machine, constructed in accordance with the invention, the device being mounted on a mold table of the machine;

FIG. 2 is a plan view of the feeding device, i.e. a sectional view taken alone II II in FIG. 1;

FIG. 3 is a sectional view taken along line III-III of FIG. 2, turned for the readers convenience; and

tubes 8.

The herein disclosed construction of the feeding device is characterized in that it provides for formation of a powder-free zone in the area of the passage of the molds, whereby the air being expelled from the molds is able to leave the apertures of the molds unobstructedly.

The fact that the powder-free zone is created with the help of a thin-walled tube enables to prolong the part of the operating cycle through which filling of the mold may be performed, since it is thus possible to fill the mold not only while the inlet of the mold enters the powder-free zone, but also while this inlet is leaving this zone.

We claim:

1. A feeding device for a rotary tablet machine for compressing powder, the machine including a rotor with a toothed rim and a rotary table having molds defining cavities mounted therein for the tablets, the device comprising: a frame which partitions defining a repowder.

2. The feeding device as defined in claim 1, wherein said delivery compartments have mounted therein blade-type agitators having driven spindles extending radially with respect to said rotary table, said spindles being driven from said toothed rim. 

1. A feeding device for a rotary tablet machine for compressing powder, the machine including a rotor with a toothed rim and a rotary table having molds defining cavities mounted therein for the tablets, the device comprising: a frame which partitions defining a receiving compartment and delivery compartments communicating with one another, said frame being non-rotatably mounted above said rotary table, said partitions having apertures made therethrough, corresponding to the diameter of said mold cavIties and extending from the bottom to the top of said partitions, said apertures communicating the interior of said molds with the ambient atmosphere as said molds are filled with the powder.
 2. The feeding device as defined in claim 1, wherein said delivery compartments have mounted therein blade-type agitators having driven spindles extending radially with respect to said rotary table, said spidles being driven from said toothed rim. 